MSCs are an important member of the bone marrow stem cell repertoire. These cells are described as nonhematopoietic stromal cells and their classical role is to support the process of hematopoiesis and HSC engraftement and to give rise to cells of mesodermal origin, such as osteoblasts, adipocytes and chondrocytes [Pittenger M F et al. 1999].
Various studies have depicted roles of MSCs, among others, their ability to transdifferentiate into cells of endodermal and ectodermal origin, including possible neural transdifferentiation and broad immunomodulating properties. In one publication it was shown that cerebrospinal fluid (CSF) of normal H-Tx rats promotes neuronal and glial differentiation from neurospheres and that the CSF from hydrocephalic H-Tx rats interferes with neuronal differentiation (Gonzales et. al. 2006). Another publication reported that CSF can promote survival and astroglial differentiation of adult human neural progenitor cells but inhibits proliferation and neuronal differentiation (Buddensiek et al. 2010)
There are recent reports that multiple intrathecal injections of mouse derived MSC neural progenitors (MSC-NPs) in an experimental model of multiple sclerosis (Harris V K et al. (2012) #1) induced a strong beneficial clinical effect on EAE. In another recent study by the same group, neurosphere-like cells were generated from multiple sclerosis patients and healthy donors (Harris V K et al. (2012) #2]. The investigators reported that multiple injections of MSC-NPs are advantageous as compared to a single injection and they improve the clinical and pathological parameters of EAE, and promote endogenous repair mechanisms.
The publications WO 2004/046348, WO 2006/134602, WO 2007/066338, WO 2009/144718 describe methods of neuronal differentiation.
Radtke et al (2009) describes the formation of neurospheres from adipose-derived stem cells and their differentiation in culture to peripheral glial-like cells.
In yet another study it was reported that CSF from healthy human donors can induce human bone marrow MSC to differentiate into neural-like cells (Ying Ye et al. (2011)).